In a fuel storage tank for a motor vehicle or other devices, a vent valve is used to permit flow of air into and out of the tank to accommodate change in the amount of fuel in the tank during refueling and ongoing consumption of fuel, as well as effects of changing ambient temperatures. Flow of air into and out of the fuel tank reduces risk of damage to the fuel tank caused by pressure changes that may be generated absent a vent valve. A modern fuel tank typically has a fill limiter vent valve to permit escape of fuel vapors from the tank during refueling, thus facilitating refueling. Fuel vapors are instead permitted to flow to an evaporative storage canister.
Vehicle manufacturers are concerned that liquid fuel may escape from the fuel tank through the fill limiter vent valve when the tank is on an incline, or when the tank is overturned, e.g. during an accident involving a rollover. Therefore, the fill limiter vent valve and other valves in the fuel storage tank typically include a secondary function of closing when liquid fuel is present at the valve. However, there is a concern that the fill limiter vent valve may become damaged and unable to seal properly against flow of liquid fuel as a result of an impact. This may result when an impact is severe enough to move the wall of the fuel tank into physical contact with a valve, restricting the valve's operation or damages the valve and limiting its ability to seal liquid fuel. Present fill limiter vent valves and other valves may be limited in their ability to adequately seal against flow of liquid fuel in event of such an impact.